Movement as medicine

The more you move, the healthier you’ll be. Jeff Sledge, a faculty associate of the Nelson Institute, lives by that code. He studies how people move around the cities in which they live, and how that affects their health.

“Going to a gym to get exercise is one option for some people. But for many they don’t have the opportunity, they are busy with work and family, or they feel their time is best spent elsewhere, says Sledge. “Regardless, the healthiest thing you can do is to arrange your life so you have the energy expenditures you need to preserve good health. It becomes a part of who you are."

Sledge studies movement and health in urban settings. He outfits people with GPS trackers, accelerometers and various health monitors.These provide data on where people travel, how much energy they expend, and other information that is downloaded into a digital map.The data reveals patterns of movement and whether a person was walking, running, cycling or driving.

Sledge was introduced to the power of dynamic GPS data as a graduate student in the Nelson Institute, earning his doctorate in Environment and Resources in 2011. As he began to explore the interface between urban environments and public health, he arrived at a novel idea: Could researchers find ways to use the environment people live in to help treat disease? And could health practitioners use environments to increase a patient’s energy expenditures and help them reach desired outcomes?

“The answer is hypothetically yes, but it depends, says Sledge, who has studied the subject for more than a decade. “This is a conversation in mid-stride."

In his current research, Sledge uses real-time assessments to study how chemotherapy, radiation or hormonal therapy impact breast cancer patients’ ability to produce energy and engage in daily activities and exercise. He is working as part of a team led by Dr. Kathy Miller of Indiana University’s Bren Simon Cancer Center and professor Steve Ventura of the Nelson Institute.

Jeff Sledge

Using a stationary bicycle made by Saris Cycle with a special protocol built into its computer, the researchers monitor and record a patient’s energy expenditures, heart rate and pedaling cadence at precise intervals. Study participants are measured on the bike before they begin cancer treatment to assess their energy output and fitness level, and again six, 12 and 18 months down the road. When outside the lab, the women wear GPS trackers and accelerometers to document how much energy they expend and where.

Sledge says one surprise finding is an order-of-magnitude loss of energy production for women as they receive cancer therapy. For example, a patient who was previously able to sustain 200 watts of energy on the bicycle might only be able to sustain 20 watts six months following treatment.

“That has dramatic consequences for how you think about where you’re going to live and how you’re going to be able to engage in an active life," Sledge explains.

Sledge and his collaborators plan to use their findings to help breast cancer survivors plan lifestyles that mitigate the negative effects of therapy and improve their health and quality of life. The more active a breast cancer survivor is, the more energy production capacity she can rebuild, he says. And survivors with higher energy levels are thought to have a smaller chance of relapse.

“If we understand how much energy a woman was normally expending, the deficit caused by her therapy, and her patterns of movement at home and work, we now look at our data differently. This has the capability to become a tool of direct, individualized intervention," he says.

The team’s second phase of research, with support from the Breast Cancer Research Foundation, will focus on building patient-centered tools. The goal is to create custom exercise plans to help women recover to their pre-treatment fitness or better while hopefully reducing the number of breast cancer recurrences.

“We want to provide physicians, recovery nursing teams and physical therapy teams with the tools to help breast cancer survivors more fully re-engage in their environments with an improved quality of life," Sledge says.

Equipped with such data during regular checkups, breast cancer survivors could review with their doctors their movement patterns and discuss strategies to increase daily energy use.'

Caloric imbalance

Certain genes that protect health are switched off by inactivity, Sledge explains, but they can be switched back on by the right kinds of movement. This “epigenetic” effect compounds the benefits of exercise, and the cumulative effect can be strong.

In separate studies, Sledge has been trying to understand how much energy a person must expend to make health transitions, specifically for metabolic diseases such as obesity and type 2 diabetes, which today overwhelm all other diseases in the United States.

“With metabolic diseases, the primary common threat is taking in too many calories for how you live and where you live," he says. “These are diseases of energy-rich environments. They are diseases of place – of industrialized countries and urbanization."

“With metabolic diseases,the primary common threatis taking in too many caloriesfor how you live and whereyou live. These are diseasesof place – of industrializedcountries and urbanization."

Sledge and a team of UW-Madison researchers studied the health and energy expenditures of school-aged children in a Milwaukee community, examining how food systems, social structures, transportation and access to exercise might influence the rate of metabolic disease.

“This environment had a terrific culture and terrific people that were incredibly supportive and concerned about the health of their children, says Sledge, but for a variety of reasons the children, who wore monitors during the study to track their physical activity, weren’t getting the mini mum amount of recommended exercise. Among the factors limiting their activity: Parents worried about the safety of their neighborhoods and about having their children walk or bike to school. Parks, open spaces and pathways weren’t being used.

The biggest surprise came when the GPS data revealed a clustering of student families in locations distant from school. The families, primarily of Hispanic heritage, felt strongly about the quality of their school and the cultural values instilled there, and would drive the students considerable distances to attend.

“Here there were cultural overlays, issues of health and security, and socioeconomic conditions that weren’t our focus at first," Sledge explains. “But as we became sensitive to the community, they emerged."

So Sledge changed tactics. His team began to teach an eighth-grade science course that deviated from the typical textbook-style approach to instead teach research methods first-hand.

“We said to the kids, ‘We want you to approach some of these issues of health in the built environment, and we want you to be the primary organizers of the research, the data collection and the analysis," Sledge recalls.

The children responded with enthusiasm, designing and executing experiments in how to increase daily energy use. Their physical activity increased and there were additional benefits: In standardized science tests, the students who participated in the citizen-science model of inquiry improved a full grade level across the board.

Reducing convenience

The potential applications of this research go beyond understanding the health of children and cancer survivors.

"Any time you can change habituated patterns of movement, you will impact health," says Sledge. "As a society, we’ve done everything we can to make life comfortable – from the shoes you walk in to the chairs you sit on, to our reliance on motorized transportation and the growing amount of ‘screen time’ in our lives. That’s really detrimental, so removing a little convenience goes a long way to improve health."

“The idea is to eventually have a cultural sea change in the way we design our built environments, how we interact with the greater biosphere through invitations to nature, and what we are willing to accept in the way that we live," he continues.

Sledge says this will involve designing urban environments around a range of human energy outputs. For example, the layout of city centers and sidewalks, the location of parking structures, and the orienting of urban development around accessible public transit can all contribute to more exercise.

“If I were to design a city today, from scratch, I would want to have a place that invites relatively high constant energy demand – a place that has impact to it, that makes you expend energy," Sledge says. But, he emphasizes, accommodations in design must also be understood and considered for those people who are going through disease processes and who have disabilities.

“The problems and challenges are far reaching, but they are not out of reach," he concludes.

Donald Radcliffe is a forest science and life sciences communication double major pursuing the environmental studies certificate.